The present invention relates to equipment for developing exposed photographic film and in particular, to equipment adapted to process a large film volume. The present invention is particularly adapted for use in connection with automatic film exposing and developing equipment such as is used in the rapidly expanding field of micro-image recordation in which a large volume of data is recorded on relatively small film, usually referred to as "microfiche". One particularly advantageous microfiche recorder is claimed and described in the commonly owned U.S. Pat. No. 3,746,444 in which a microfiche, after its exposure, is automatically severed from a supply spool and fed to a film processor where the exposed emulsion side of the film is sequentially subjected to the usual processing liquids. Thereafter the fiche is dried and ready for use.
Although the specific construction of the film processor is not described in detail in the above-referenced U.S. patent, processors as such are well-known in the art. U.S. Pat. Nos. 3,192,846; 3,344,729; 3,405,626; and 3,545,964 describe recent attempts to construct efficient, high-speed automatic film processors.
Although the processors described in the referenced patents constitute certain improvements over earlier automatic processors, they have a number of shortcomings. For example, the prior art processors attempt to flood the whole fiche, that is, normally both sides thereof, with processing liquid while it is normally only necessary to subject the emulsion side of the fiche to the liquid. This flooding of the fiche is wasteful of processing liquid and, more importantly, requires a relatively complicated liquid distribution and collection system. This renders such processors unnecessarily expensive.
Furthermore, prior art processors exercise little control over the return of the processing liquid to a collection point, e.g., a collection bottle disposed beneath the processor as such. Normally a drainage opening is provided for each processing compartment which is connected with the collection bottle via a suitable conduit such as a plastic hose. The liquid is permitted to run freely from the compartment to the bottle. The hose diameter is relatively large to prevent debris that might collect therein from blocking the hose and to prevent the formation of flow blocking air bubbles (such as are sometimes experienced in conventional sink drains) at the drainage hole. As a consequence, the liquid was permitted to gravitationally cascade through the hose into the bottle. This turbulent, uncontrolled flow of processing liquid has a tendency to draw air into the conduit and, sometimes, into the bottle. Since certain of the processing liquids oxidize this construction of the drainage system could prematurely render the liquid useless and require its replacement due only to oxidation caused by air entrapments. Again, this is expensive and increases the overall cost of operating prior art processors.
Additionally, prior art processors were relatively cumbersome to maintain and frequently required lengthy disassembly for normal service. This resulted in increased service costs and prolonged machine downtimes which again is highly undesirable, particularly for the high volume operations normally associated with automatic film processors. Furthermore, the fiche sometimes wedged as it was transported through the processor. This could lead to a jamming which required the opening of the processor and the manual, time-consuming removal of the jammed fiche. Similarly, prior art processors often had large, flat surfaces, past which the fiche travelled. Even slight pressure differentials between the fiche sides could cause the fiche to adhere to such a surface and effectively render it immovable, again requiring the time-consuming and expensive opening of the processor.